Loop fabrics, in particular terry cloth, are normally manufactured as three-weft or four-weft goods. The manufacture of four-weft goods is associated with higher costs and is therefore only specified in determined cases. By far the greatest part of terry cloth is manufactured as three-weft goods. The terry goods may have pile loops on one side, on both sides and/or on alternate sides. The appearance of the terry goods and their quality is substantially influenced by the pile change, i.e. in the mutual change of the pile loops from one side of the goods to the other. Although clean contour edges are obtained with four-weft goods, this is only the case to a limited extent with three-weft goods.
In the so called "BV pile change" (Burkhart-Vossen), clean contour edges are in fact obtained, but the pile thread is not securely tied up, because with this weave structure no ground warp change occurs and it can therefore be easily pulled out.
In the so called "Southern German pile change", the pile loops on both sides of the transition do not have the same height as in the remaining fabric surface, but on the other hand the loop strength is admittedly good because the loop thread is retained in crossing points of the ground warp.
A three-weft loop fabric is disclosed, in which the pile thread loops have the same loop height even during the pile change. For this purpose during the pile change a fourth pick and two picks without weft yarn are provided in the foundation and pile thread weave in order to securely tie in the pile thread during the transition. In order to achieve this during the pile change and during the insertion of the picks without weft yarn, the fabric feed is interrupted.
The advantages of the invention are essentially regarded as being that the pile loops in the region of the pile change have the same height as in the remaining fabric surface and that the pile thread in the region of the pile change is securely tied up. This process is universal in the manufacture of three-weft loop fabric and can be used without conversion in every conventional loom and also in modern looms with a missed pick device.